This application is for continuation of a toxicology training program at University of Maryland (UM). The objective is to train graduate students and postdoctoral fellows in neurotoxicology, cell injury and carcinogenesis, molecular epidemiology and aquatic toxicology, with special emphasis on mechanisms and application of cutting-edge technologies to toxicological research. This proposal brings together a cadre of well funded, highly productive faculty mentors from different sites within the UM System, including the School of Medicine (SOM) and the Chesapeake Biological Laboratory. Mentors form a cohesive program designed to prepare trainees for research careers in toxicology and environmental health sciences. One of the major strengths is the exposure of the students to translational aspects of basic research in toxicology. Chemical risk assessments and the development of countermeasures to treat and/or prevent disease states induced by toxicants depends on the determination of the mechanisms by which such toxicants act, on the identification of targets for therapeutic intervention, and on the characterization of new assays, models, tools, and technologies for toxicity testing. Thus, mentors have been selected for their common interest in basic, clinical and ecological research applied to such environmental toxicants as metals, phytoestrogens, dioxins, and insecticides, and interests span from basic to clinical and environmental research. This selection provides trainees with a unique opportunity to gain experience in fields that play a major role in determining the mechanism of action and the effects of environmental toxicants in susceptible subsets of the population, including sensitive stages of development. The graduate training in toxicology combines resources of the UM system-wide Program in Toxicology and the SOM Pharmacology and Experimental Therapeutics Departmrnt (toxicology track), and includes didactic course work, laboratory rotations, seminars, research and participation in national meetings. The postdoctoral program includes training in state-of-the-art toxicology research, teaching experience, and participation in seminars and national meetings. The breadth of the program is sufficient to allow emphasis in four primary areas: The Neurotoxicology Track provides training in molecular mechanisms of neurodegeneration due to environmental toxicants and the development of chemo- and gene therapy modalities. The Cell Injury and Carcinogenesis Track provides training in the action of free radicals, calcium homeostasis, mechanisms of lead and dioxin toxicities, estrogen biosynthesis and carcinogenesis. The Molecular EpidemiologyTrack provides training in identification of biomarkers of exposure and susceptibility, and in epidemiological methods for identifying associations between environmental chemical exposures and diseases. The Aquatic Toxicology Track provides training in pathobiology, immunotoxicology and molecular mechanisms of toxicity of heavy metals, dioxin and other pollutants.